Re: [PATCH v2] send-email: try to get fqdn by running hostname --fqdn on Linux and macOS

> On 12 May 2025, at 11:05 PM, Junio C Hamano <gitster@pobox.com> wrote:
> 
> Aditya Garg <gargaditya08@live.com> writes:
> 
>>>> On 12 May 2025, at 10:12 PM, Junio C Hamano <gitster@pobox.com> wrote:
>>> 
>>> "Julian Swagemakers" <julian@swagemakers.org> writes:
>>> 
>>>> There are multiple implementations of the hostname command, and they
>>>> don't all support `--fqdn`. For example this will not work on Alpine
>>>> Linux as well as macOS.
>>>> ...
>>>> All seem to support `-f` though, maybe that would be the better option.
>>> 
>>> What makes me worried about such a proposed changes is if there are
>>> implementations that takes `-f` but uses it to mean something
>>> completely different from fqdn, and emits something that looks like
>>> a hostname but is not.  At least an implementation that takes --fqdn
>>> without erroring out would try to give what this code wants to find
>>> out (or it is simply crazy), but -f does not feel specific enough.
>> 
>> What we can do is use `hostname -f` for macOS, after all its the only darwin based
>> OS used rn, and use hostname --fqdn for Linux.
>> 
>> Although it still leaves out Alpine Linux.
> 
> As long as we record the reasoning behind our decision to use `-f`,
> with an explanation like "we can add a configuration to disable this
> if an odd platform implementation of `hostname -f` truly misbehaves"
> to suggest that we can, if needed, easily give an escape hatch if
> this change breaks existing users, I think it is OK to just use
> `-f`, which would be the simplest ;-)